﻿// Copyright (c)  YISH. All rights reserved.
// Licensed under the MIT License, See License.txt in the project root for license information.

using NSQL.Sharpen;

namespace NSQL.Expressions
{
    public class NullExpression : BaseExpression, INullExpression
    {
        public IExpression Expr { get; set; }

        public NullExpression(IExpression expression) => Expr = expression;

        public override T Accept<T>(IExpressionVisitor<T> visitor) => visitor.Visit(this);
        public override void Accept(IExpressionVisitor visitor) => visitor.Visit(this);
        public override bool IsValid => Expr.IsValid;
        protected override IExpression DeepCopy()
        {
            return new NullExpression(Expr.DeepClone())
            {
                Tag = Tag
            };
        }
    }
}